This invention relates generally to the field of hand held liquid dispensers of a type used, for example, in the spraying of liquid insecticides, fungicides, window-cleaning solutions, and the like, and more particularly, it is directed to an improved charging device permitting the user to conveniently make a solution from a premeasured liquid concentrate without the necessity of contacting the materials used and without the danger of spillage.
It is known in the art to provide dispensers containing a concentrate of soluble materials to a fixed quantity of solute, usually water, for dispensing as a spray upon an object to be treated. A typical device of this type is disclosed in U.S. Pat. No. 4,705,191 to Itzel, et al.
As disclosed in this patent, the concentrate is contained within a threaded cap which is ruptured as the cap is threadedly engaged upon the container containing the solute, permitting the contents to fall into the solute for mixing.
While not without considerable utility, this construction has several shortcomings, including the inability of the user to determine when rupture has occurred. Should the concentrate be of the same color as the solute, the user has no way of knowing that the concentrate has become released and dissolved or mixed with the solute without removing the charging device from the container.
Another problem lies in the fact that the point at which rupture of the capsule occurs depends upon the engagement of the capsule with portions of the threaded container which do not effect a sealing relation between the cap and the container. Thus, it is possible to have the capsule rupture before the cap is completely engaged upon the neck of the container, and if, at that point, the container is shaken, or otherwise manipulated for mixing, leakage of the contents of the container may occur.